The present invention relates to a dispenser which is provided with a pump device and in which two hollow pistons are provided which can be displaced coaxially one within the other and wherein one piston is seated on the pump base and the other piston is seated on an actuating button which extends into a mouthpiece. The hollow pistons are surrounded by a bellows which causes axial restoration, and which extends from the pump base up to the upper region of the hollow piston on a side of the actuating button.
A dispenser of this type is disclosed in French Patent 1 302 037. There a part of the mass which flows centrally through the hollow pistons also passes through the annular space formed by the surrounding bellows. For this purpose both hollow pistons, which can be displaced with respect to each other, have passage openings. As a result thereof, the substance comes into maximum surface contact with the bellows. Depending on the bellows material used and on the type of the substance, this can result in impairment of the taste or, in general, of a qualitative nature. It also frequently can be noted with such dispensers that the substance dries out and, in particular, also loses its aroma due to insufficient sealing.